A neighbourhood book exchange works best when its purpose is easy to understand. Begin with a small shelf in a suitable shared space and permission from the people responsible for that location. Keep access, weather and everyday movement in mind.
Agree on a few practical rules: which books are welcome, who checks the shelf and how unwanted material will be handled. Clear responsibilities prevent a generous idea from becoming an unattended storage problem.

Make participation optional and straightforward. People should be able to browse without giving personal details or feeling obliged to contribute. Include different reading levels and interests where the available collection allows.
Review the exchange after a few weeks. Notice which books move and whether the space remains tidy. A modest collection that is regularly used can serve neighbours better than an ambitious project with no one available to maintain it.